The outcome may indicate how the dialectic between supranationalism and nationalism will play out in much of the rest of the world.

The United Kingdom’s “Remainers,” who still hope to reverse Britain’s decision to leave the European Union, have placarded British cities with a simple question: “Brexit – Is It Worth It?”

Well, is it? The answer given by economics is clear: certainly not. In terms of the costs and benefits of leaving, the result of the 2016 Brexit referendum was plainly irrational.

And yet economics also clearly shaped the decision. The Brexit propagandists brilliantly channeled palpable economic resentment, especially against immigration, into hostility toward the EU. But the resentment was against the home-grown damage inflicted on the British economy by its neglectful rulers. As Will Hutton and Andrew Adonis note in Saving Britain, “Our problems are made in Britain; they can only be solved in Britain. Europe does not impede this mission…”

But the authors miss Brexit’s crucial non-economic dimension. Britain has never been part of a European state. Although the EU is far from the “superstate” of Margaret Thatcher’s nightmare, its governmental aspirations lack legitimacy to many. Despite talk o European citizenship, politics remain obstinately national. Britain’s Leave campaign was also a revolt against the pretension of supranational government.

So Brexit’s outcome may indicate how the dialectic between supranationalism and nationalism will play out in much of the rest of the world.

At this writing, the endgame is far from clear. There are four possibilities.

One possibility is that Britain doesn’t leave the EU after all. The organizers of a campaign for a “people’s vote” – a second referendum on the final exit terms – believe that when people know the true cost of leaving, they will reverse the decision taken in 2016.

A second possibility is that Britain “crashes out” of the EU on March 29, 2019, with no divorce deal. In this case, forecasters paint a doomsday scenario of economic collapse, gridlock on roads and rail, shortages of food, medicine, and fuel: 1940 all over again (but not exactly Britain’s finest hour).

A third possibility is half in, half out. Approved by the Cabinet in July at the prime minister’s country house, the so-called Chequers plan proposes that when Britain leaves the EU, the two sides enter into a freetrade agreement covering goods and agricultural produce, but not services – a heroic attempt to solve the Irish border problem, and avoid a customs border between two parts of the UK.

The Brexiteers oppose this, because it implies too much integration with the EU. But so do EU leaders: Britain cannot be allowed to be in for some purposes and out for others. The final possibility is another “half in, half out” scenario. Britain would leave the customs union, but remain in the European Economic Area, which includes the 28 members of the EU plus Norway, Liechtenstein, and Iceland. EEA countries set their own tariffs but follow nearly all other EU rules and pay contributions to the EU budget – even more anathema to hardline Brexiteers.

So what will happen? Most bets are on Britain formally leaving the EU in March 2019, but “temporarily” remaining in the customs union, giving it two or three years to negotiate the final divorce settlement. The referendum will be honored, but its harsh consequences postponed: a triumph of pragmatism over ideology. John Maynard Keynes put it well: “Words ought to be a little wild, for they are the assault of thoughts upon the unthinking,” he wrote in 1933. “But when the seats of power have been attained there should be no more poetic license. On the contrary, we have to count the cost down to the penny which our rhetoric has despised.”

Politicians exist to give voice to resentments bottled up by “unthinking” conservatism. They let loose feelings which we would be better off without, but whose suppression threatens political explosions. But it is also their job to ensure that such irruptions do not have extreme consequences. From time to time, the balancing act breaks down, as it did in 1914, and again in the 1930s. But mostly politicians do their double job, which, in the last analysis, is to preserve domestic and international peace.

Thus, the Brexit compromise, if it happens, may be a moderately optimistic foretaste of the fate of populism in our century. The resurgence of economic nationalism, which unites Brexit, Trumpism, and the European far right, will not lead to the breakdown of trade, hot wars, dictatorship, or rapid de-globalization. Rather, it is a loud warning to the political center – one that may cause even the current crop of extremists to shrink from the consequences of their words.